BerriAI/litellm · error · ValueError

Parameter {k} is not supported for model {model}. Supported

Error message

Parameter {k} is not supported for model {model}. Supported parameters are {supported_params}. Set drop_params=True to drop unsupported parameters.

What it means

Error "Parameter {k} is not supported for model {model}. Supported parameters are {supported_params}. Set drop_params=True to drop unsupported parameters." thrown in BerriAI/litellm.

Source

Thrown at litellm/llms/fal_ai/image_generation/stable_diffusion_transformation.py:120

                if k in supported_params:
                    # Use mapped parameter name if exists
                    mapped_key = param_mapping.get(k, k)
                    mapped_value = non_default_params[k]

                    # Transform specific parameters
                    if k == "response_format":
                        # Map OpenAI response formats to image formats
                        if mapped_value in ["b64_json", "url"]:
                            mapped_value = "jpeg"
                    elif k == "size":
                        # Map OpenAI size format to Stable Diffusion image_size
                        mapped_value = self._map_image_size(mapped_value)

                    optional_params[mapped_key] = mapped_value
                elif drop_params:
                    pass
                else:
                    raise ValueError(
                        f"Parameter {k} is not supported for model {model}. Supported parameters are {supported_params}. Set drop_params=True to drop unsupported parameters."
                    )

        return optional_params

    def _map_image_size(self, size: str) -> Any:
        """
        Map OpenAI size format to Stable Diffusion image_size format.

        OpenAI format: "1024x1024", "1792x1024", etc.
        Stable Diffusion format: Can be preset strings or {"width": int, "height": int}

        Available presets:
        - square_hd
        - square
        - portrait_4_3
        - portrait_16_9
        - landscape_4_3 (default)

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Remove the unsupported parameter or set drop_params=True.

When it happens

Trigger: Thrown at litellm/llms/fal_ai/image_generation/stable_diffusion_transformation.py:120 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/72819c01bb38840f. Report an issue: GitHub.